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    <title id="jy143030">gpstart</title>
    <body>
        <p>Starts a Greenplum Database system.</p>
        <section id="section2">
            <title>Synopsis</title>
            <codeblock>gpstart [-d &lt;master_data_directory>] [-B &lt;parallel_processes>] [-R]
        [-m] [-y] [-a] [-t &lt;timeout_seconds>] [-l &lt;logfile_directory>] 
        [--skip-heap-checksum-validation]
        [-v | -q]

gpstart -? | -h | --help 

gpstart --version</codeblock>
        </section>
        <section id="section3">
            <title>Description</title>
            <p>The <codeph>gpstart</codeph> utility is used to start the Greenplum Database server
                processes. When you start a Greenplum Database system, you are actually starting
                several <codeph>postgres</codeph> database server listener processes at once (the
                master and all of the segment instances). The <codeph>gpstart</codeph> utility
                handles the startup of the individual instances. Each instance is started in
                parallel.</p>
            <p>As part of the startup process, the utility checks the consistency of heap checksum
                setting among the Greenplum Database master and segment instances, either
                enabled or disabled on all instances. If the heap checksum setting is different
                among the instances, an error is returned and Greenplum Database does not start. The
                validation can be disabled by specifying the option
                    <codeph>--skip-heap-checksum-validation</codeph>. For more information about
                heap checksums, see <xref
                    href="../../admin_guide/highavail/topics/g-enabling-high-availability-features.html"
                    format="html" scope="external">Enabling High Availability and Data Consistency
                    Features</xref> in the <cite>Greenplum Database Administrator Guide</cite>.</p>
            <note>Before you can start a Greenplum Database system, you must have initialized the
                system using <codeph>gpinitsystem</codeph>. Enabling or disabling heap checksums is
                set when you initialize the system and cannot be changed after
                initialization.</note>
            <p>If the Greenplum Database system is configured with a standby master, and
                    <codeph>gpstart</codeph> does not detect it during startup,
                    <codeph>gpstart</codeph> displays a warning and lets you cancel the startup
                    operation.<ul id="ul_v3p_mrc_nlb">
                    <li>If the <codeph>-a</codeph> option (disable interactive mode prompts) is not
                        specified, <codeph>gpstart</codeph> displays and logs these
                            messages:<codeblock>Standby host is unreachable, cannot determine whether the standby is currently acting as the master. Received error: &lt;error>
Continue only if you are certain that the standby is not acting as the master.</codeblock><p>It also
                            displays this prompt to continue
                            startup:<codeblock>Continue with startup Yy|Nn (default=N):</codeblock></p></li>
                    <li>If the <codeph>-a</codeph> option is specified, the utility does not start
                        the system. The messages are only logged, and <codeph>gpstart</codeph> adds
                        this log
                        message:<codeblock>Non interactive mode detected. Not starting the cluster. Start the cluster in interactive mode.</codeblock></li>
                </ul></p>
            <p>If the standby master is not accessible, you can start the system and troubleshoot
                standby master issues while the system is available.</p>
        </section>
        <section id="section4">
            <title>Options</title>
            <parml>
                <plentry>
                    <pt>-a</pt>
                    <pd>Do not prompt the user for confirmation. Disables interactive mode.</pd>
                </plentry>
                <plentry>
                    <pt>-B <varname>parallel_processes</varname></pt>
                    <pd>The number of segments to start in parallel. If not specified, the utility
                        will start up to 64 parallel processes depending on how many segment
                        instances it needs to start.</pd>
                </plentry>
                <plentry>
                    <pt>-d <varname>master_data_directory</varname></pt>
                    <pd>Optional. The master host data directory. If not specified, the value set
                        for <codeph>$MASTER_DATA_DIRECTORY</codeph> will be used.</pd>
                </plentry>
                <plentry>
                    <pt>-l <varname>logfile_directory</varname></pt>
                    <pd>The directory to write the log file. Defaults to
                            <codeph>~/gpAdminLogs</codeph>.</pd>
                </plentry>
                <plentry>
                    <pt>-m</pt>
                    <pd>Optional. Starts the master instance only, which may be useful for
                        maintenance tasks. This mode only allows connections to the master in
                        utility mode. For example:</pd>
                    <pd>
                        <codeblock>PGOPTIONS='-c gp_session_role=utility' psql</codeblock>
                    </pd>
                    <pd>The consistency of the heap checksum setting on master and segment instances
                        is not checked.</pd>
                </plentry>
                <plentry>
                    <pt>-q</pt>
                    <pd>Run in quiet mode. Command output is not displayed on the screen, but is
                        still written to the log file.</pd>
                </plentry>
                <plentry>
                    <pt>-R</pt>
                    <pd>Starts Greenplum Database in restricted mode (only database superusers are
                        allowed to connect).</pd>
                </plentry>
                <plentry>
                    <pt>--skip-heap-checksum-validation</pt>
                    <pd>During startup, the utility does not validate the consistency of the heap
                        checksum setting among the Greenplum Database master and segment instances.
                        The default is to ensure that the heap checksum setting is the same on all
                        instances, either enabled or disabled.
                        <note type="warning">Starting Greenplum Database without this validation
                            could lead to data loss. Use this option to start Greenplum Database
                            only when it is necessary to ignore the heap checksum verification
                            errors to recover data or to troubleshoot the errors.</note></pd>
                </plentry>
                <plentry>
                    <pt>-t <varname>timeout_seconds</varname></pt>
                    <pd>Specifies a timeout in seconds to wait for a segment instance to start up.
                        If a segment instance was shutdown abnormally (due to power failure or
                        killing its <codeph>postgres</codeph> database listener process, for
                        example), it may take longer to start up due to the database recovery and
                        validation process. If not specified, the default timeout is 600
                        seconds.</pd>
                </plentry>
                <plentry>
                    <pt>-v</pt>
                    <pd>Displays detailed status, progress and error messages output by the
                        utility.</pd>
                </plentry>
                <plentry>
                    <pt>-y</pt>
                    <pd>Optional. Do not start the standby master host. The default is to start the
                        standby master host and synchronization process.</pd>
                </plentry>
                <plentry>
                    <pt>-? | -h | --help</pt>
                    <pd>Displays the online help.</pd>
                </plentry>
                <plentry>
                    <pt>--version</pt>
                    <pd>Displays the version of this utility.</pd>
                </plentry>
            </parml>
        </section>
        <section id="section5">
            <title>Examples</title>
            <p>Start a Greenplum Database system:</p>
            <codeblock>gpstart</codeblock>
            <p>Start a Greenplum Database system in restricted mode (only allow superuser
                connections):</p>
            <codeblock>gpstart -R</codeblock>
            <p>Start the Greenplum master instance only and connect in utility mode:</p>
            <codeblock>gpstart -m 
PGOPTIONS='-c gp_session_role=utility' psql</codeblock>
        </section>
        <section id="section6">
            <title>See Also</title>
            <p><xref href="gpstop.xml#topic1">gpstop</xref>, <xref href="gpinitsystem.xml#topic1"
                /></p>
        </section>
    </body>
</topic>
